1) Technical Field
The subject invention generally relates to an air filtration system for filtering air between a head and body of a user and an environment external to the user. The air filtration system is utilized in the medical profession during surgical procedures. The subject invention more specifically relates to a helmet assembly and gown for use in the air filtration system.
2) Description of the Prior Art
Air filtration systems and helmet assemblies utilized in the air filtration systems are known in the art. As indicated above, air filtration systems and helmet assemblies are worn by users throughout the medical profession, such as surgeons, during surgical procedures for filtering air between a head and body of the surgeon and an external environment, such as a clean room.
Conventional air filtration systems and helmet assemblies are deficient for one reason or another. For example, U.S. Pat. No. 5,592,936 to Thomas, Jr. et al. discloses an air filtration system and helmet assembly that draws air through a filter medium into the helmet assembly and through an intake grid where the air is then channeled through an air flow channel over a face of the user. The air filtration system and helmet assembly of this patent are deficient in that air is not distributed completely about the head of the user. That is, air is not distributed to a back of the head, toward a neck, of the user. Further, the intake grid is deficient in that the grid does not extend between a front and rear section of the helmet assembly to maximize an effective intake area for the filter medium.
A further example of a conventional air filtration system and helmet assembly is disclosed in U.S. Pat. No. 5,054,480 to Bare et al. This patent discloses an air filtration system and helmet assembly that draws air into the helmet assembly via an intake fan, and exhausts air from the air filtration system and helmet assembly via an exhaust fan disposed at the rear section of the helmet assembly spaced away from the neck of the user. The air filtration system and helmet assembly of this patent is deficient in that they are overly heavy due to the additional fan required to exhaust air. Furthermore, the exhaust fan creates excessive strain, and therefore fatigue, in the neck of the user because the exhaust fan is spaced away from the neck of the user.
The conventional air filtration system and helmet assembly disclosed in U.S. Pat. No. 5,711,033 to Green et al. is also deficient. This patent discloses an air filtration system and helmet assembly that draws air into the helmet assembly through an intake fan and scroll housing disposed at a rear section of the helmet assembly. The air filtration and helmet assembly of this patent is deficient because the intake fan and scroll housing are spaced away from the neck of the user. Further, the scroll housing in this patent includes only one air outlet to distribute air about the head of the user resulting in less balanced air flow throughout the helmet assembly. Additional drawbacks of such an air filtration system and helmet assembly including only one air outlet from the scroll housing are excessive fog build-up and poorer heat dissipation in the helmet assembly.
Other conventional air filtration systems and helmet assemblies are also deficient for the following reasons. First, these conventional air filtration systems and helmet assemblies do not assist a single user in self-gowning as the surgeon maintains sterility. That is, these air filtration systems and helmet assemblies do not include a positioning and supporting system that automatically centers a face shield over the helmet assembly and that supports an entire weight of the gown and face shield. Instead, the conventional air filtration systems and helmet assemblies merely utilize hook-and-loop fasteners randomly places around the helmet assembly to connect the face shield to the helmet assembly in any orientation. Furthermore, randomly-placed hook-and-loop fasteners do not automatically center the face shield and do not support the entire weight of the gown and the face shield as the surgeon self-gowns. Instead, as the user self-gowns, he or she must repeatedly adjust the face shield in order to center the face shield. This is time consuming and burdensome.
Secondly, it is generally understood that the amount of air flowing into the helmet assembly is critical for anti-fogging and heat control purposes. However, the air filtration systems and helmet assemblies of the prior art do not assist the surgeon in recognizing the amount, or volume, of air flowing into the helmet assembly. That is, these air filtration systems and helmet assemblies do not provide audible indication to the surgeon of the volume of air flowing into the helmet assembly during any particular surgical procedure.
Thirdly, as discussed above, it is ideal to position and maintain any fans in the air filtration system and helmet assembly as directly over, and not spaced from, the neck of the user as possible in order to minimize strain and fatigue. The prior art air filtration systems and helmet assemblies do not incorporate a strap flexibly connected to the front section of the helmet assembly such that the strap is pulled from the front section of the helmet assembly and the weight of any fans is maintained over the user""s neck when the helmet assembly is adjusted to fit various sized heads.
Due to the inefficiencies identified in such conventional air filtration systems and helmet assemblies, it is desirable to implement a novel air filtration system and helmet assembly that utilizes a single fan to distribute air toward both the face and the neck of the user and that includes a scroll housing that includes at least two air outlets for complete balancing of the air flow about the head of the user. It is also desirable to dispose the fan in the helmet assembly such that it is not spaced away from the neck of the user to minimize strain, and to include an intake grid that extends between front and rear sections of the helmet assembly to maximize the effective intake area for filtering the air. Finally, it is desirable to implement an air filtration system and helmet assembly that includes a positioning and supporting system to assist the user in self-gowning, that includes audible indication to the user of the volume of air flowing into the helmet, and that includes a strap that can be adjusted to fit different sizes of heads while maintaining the weight of the helmet assembly over the neck of the user.
An air filtration system for filtering air and a helmet assembly for use in the air filtration system is disclosed. The air filtration system and helmet assembly are utilized in the medical profession during surgical procedures to filter air between a head and body of a user, such as a surgeon, and an environment external to the user. As appreciated by those skilled in the art, the subject invention, in addition to air filtering, assists in controlling carbon dioxide concentration, dissipating heat, and anti-fogging within the helmet assembly. It is to be understood that the subject invention can also be utilized in other situations requiring filtered air including, but not limited to, the manufacturing of semi-conductor chips and other computer components in manufacturing clean rooms.
The air filtration system and helmet assembly include an inner structural shell and an outer structural shell. The outer structural shell extends from the inner structural shell to define at least one air flow channel between the inner and outer shells for channeling air about the head of the user. The helmet assembly further includes a base section and a facial section extending from the base section to define a facial opening.
A fan module is mounted to at least one of the inner and outer shells, and a scroll housing is mounted adjacent the fan module. More specifically, the fan module includes a fan and a motor, and the scroll housing includes at least one air inlet and at least one, preferably at least two, air outlets. The fan module, including both the fan and the motor, is disposed at the rear section of the base section. In operation, the fan module, specifically the fan, draws air into the air inlet and distributes air out of the scroll housing through the air outlet or outlets and into the air flow channel.
The subject invention also incorporates at least two helmet air exits, preferably a front and rear air helmet air exit for distributing air from the air flow channel toward the head of the user. More specifically, the front and rear air exits are disposed at the front and rear sections of the helmet assembly, respectively. The front and rear air exits are in fluid communication with the air flow channel and the air outlets. The front air exit distributes air from the air flow channel toward a front, or face, of the head of the user, and the rear air exit distributes air from the air flow channel toward a back, or neck, of the head of the user. As such, a single fan is utilized to distribute air toward both the face and the neck of the user. The air outlet or outlets of the scroll housing completely balance the air flow about the head of the user between the front and rear air exits. Further, because the fan is disposed at the rear section of the base section of the helmet assembly, the fan is not spaced away from the user""s neck and strain and fatigue in the user is minimized.
The air filtration system further includes a gown having a body portion and a head portion. The body portion covers at least a portion of the body of the user and the head portion covers the base section of the helmet assembly. The head portion of the gown operates as a filter medium to filter air between the user and the external environment. The gown also includes a skirt. More specifically, the skirt is removably attached to the body portion of the gown exclusively at a front of the gown. An intake grid is mounted to the outer shell of the helmet assembly for user with the gown. The intake grid is contoured to the outer shell between the front section and the rear section of the base section to maximize an effective intake area for the filter medium to filter air drawn into the scroll housing.
The subject invention further includes a face shield mounted to the head portion of the gown to cover the facial opening. As such, the user can view through the head portion of the gown. Depending on the particular embodiment of the subject invention, the face shield includes either a mounting mechanism or a first visual indicator. These will be described further below.
Also depending on the particular embodiment, the base section of the helmet assembly includes either a mounting device or a second visual indicator positioned, preferably centered, relative to the facial opening. If the helmet assembly includes the mounting device, the mounting device interlocks with the mounting mechanism on the face shield. As such, the subject invention provides a positioning and supporting system that automatically centers the face shield over the facial opening and that preferably supports the entire weight of the gown in order to assist the single user in self-gowning as the user maintains sterility. On the other hand, if the helmet assembly includes the second visual indicator, then the second visual indicator aligns with the first visual indicator on the face shield. As such, the subject invention provides a visual positioning system that automatically centers the face shield over the facial opening thereby assisting the single user is self-gowning as the user maintains sterility.
The subject invention also includes a controller that operates with a power supply to control the amount, or volume, of air into the air filtration system and helmet assembly and to provide audible indication of the volume of air to the user while the user is wearing the air filtration system and helmet assembly during the surgical procedure. Preferably, the power is integrally disposed within the helmet assembly. The air filtration system and helmet assembly of the subject invention also include a strap flexibly connected to the helmet assembly such that the strap is pulled from the front section of the helmet assembly. As a result, the weight of the fan is maintained over the user""s neck when the helmet assembly is adjusted to fit various sized heads.
The subject invention further includes a method for maintaining a constant volume of air flowing into an air filtration system during the entire use of the air filtration system. The method includes the steps of selectively activating and deactivating the power supply at a first activation rate to distribute a required voltage to the motor. This step establishes a rotational speed for the fan that correlates to the constant volume of air flowing into the air filtration system. Next, the method monitors the back electromotive force of the motor of the helmet assembly to determine the rotational speed of the fan as well as when the rotational speed of the fan has stabilized for some predetermined period of time. The voltage of the power supply is monitored after the rotational speed of the fan has stabilized for the predetermined period of time. Finally, the power supply is selectively activated and deactivated at a second activation rate as the monitored voltage of the power supply decreases. This step sustains the required voltage that is distributed to the motor such that the constant volume of air flowing into the air filtration system is maintained throughout the entire use of the air filtration system.
Accordingly, the subject invention provides an air filtration system and helmet assembly that overcomes the deficiencies in the prior art as identified above.